Safety switch for stranding machines



Jane 1950 c. o. BRUESTLE ET AL. 2,495,886

SAFETY SWITCH FOR STRANDING MACHINES Filed Aug. 18, 1948 INVENTORS CARL O. BRUESTLE BY HUGO WILKEN ATTORNEYS Patented Jan. 31, 195

UNITED PATENT OFFICE SAFE-TY SWITCH FOR STRAN-DING MACHINES 9 Clai s.

The p e inve ien relat s e e ewiten er utilization particularly with a stranding machine. Such machines wis together e lu a i y of strands of wire, hemp or the like and it essential that t e machine be P esent t a tep in he v nt hat one of the St? fi re k The presen nv ntion aeeernplieh e t e ebieet mentioned above in a very simple manner and is so constructed as to be operable even when the tension on the strands is very small.

It is an object of the invention to provide a sw to s p a stranding ma hine 1 1, 9 the breakage of one or more of the strands Whieh are being twisted.

It is another object of the invention to provide such a switch which will Qperate upon very small differential in the tension applied to the strand cable as a whole.

It is another object of the invention to provide such a switch which is economically built and which is rugged and capable of reliably perform.- ing its function for long periods of time.

Other objects and features of the invention will appear when the following description is ,consielered in connection with the annexed drawings in which- Figure 1 is a side elevation of a switch mecha: nism of our invention;

Figure 2 isan end elevation of the device of Figure l, the view being taken from the right; and

Figure 3 is a top plan iew of the switch of Figures 1 and 2.

Referring now to the drawings, It represents a supporting plate, the sides II and 52 of which are bent forwardly to form supports for various parts of the apparatus. Likewise, the base of plate it is bent forwardly and upwardly as indicated at 3 and :4, respectively, to form additional supports for operating parts of the device as well as to form, together with a cover 55, an enclosure for the major portion of the device.

Mounted in an upward extension .of the plate Iii is a stub shaft I! on which two pulleys l8 and 28 are rotatably supported.

Mounted in the plate Ill and the bent-over upwardly extending portion M thereof is a pin or shaft 2! on which is a bearing 22 which in turn supports a generally rectangular block 23. Fixed to the block 23 as by Welding is a channel member 2 which thus forms a pivoted arm. At the upper end of the arm 24 there is mounted a second stub shaft 25, carrying the two rollers 26 and '21.

The one arm of the angle from which member 24 is formed is provided with a slot 28 into which extends he e d f e he ze t v ex end n s ew when n is hreade r rri' nnte b 3! welde i en ie "t "l e i l end n left been Per 'n I 'e t e S t rti r ete t s rew e! is e ieeld w th e 33+ en a nen ee eel leer Z n thereof e n 33 extends from washer 32 to a second was 5 wh ch bear a ainst th fo dl sea eer e f he an le i em whi 2 ormed e s m unted in the angle nert en IEQl-Qr tiened is an ustabl new 35 Wh eh. when he a i in t e esi i n she n been eseifn the ea t ai 5 pi e niereswiten 3. Wnien wi h s f stened t9 h enpne t ne lat l9 any suitab manner.

A ea. me r m a rvire s and n m h ne i ind eeted a 133- Th s ca le pas es b nea t pul e l8 henc b nea h t e p e 2 an Ire e th pu le 26 a n th top the of to th t p at p le Zathen a und that m ler un r ulle 2? and around pulley 2? to the usual drawing capstan at. Due t t moun n o th p ll ys 25 and on the sp n p s d ar it i n9 sible to cause the arm to move in clockwise die tio as s e in Fi ur 1 Wh n t teneie 9n the arm 24, due to the passage of the wire over the pulley 2 an hereen come l ss t the pressure ex d by th p in 36- Sine the micre w eh 3. i ope ed b me emen 9 the arm 24 to the position shown in Figure '1, the circuit to the driving motor of the strander, well as the capstan 5!}, will be broken immediately upon the arm 2.4 co nin int? t e pee qn shown in Figure 1. Pressure exerted by spring 33 mayobviouslybe .yaried by adjustment of the position of screw 3!). This pressure is determined in accordance with the tension desired ou the wire strands as modified by the pulley arrangement.

In a particular instance, three strands are roads into a cableand a tension of one pound per g is maintained. Utilizing the particular arrangement disclosed, a force of appro in twelve pounds acts upon the arm 29 to draw 1 to the left or in a counterclockwise direction. In this instance the screw 30 is adjusted so that the spring 33 exerts a pressure of approximately nine pounds in a clockwise direction. Thus, while the machine is operating normally, the pivoted switch arm 24 lies to the left and the contacts of the microswitch are closed. If a strand of wire breaks, the tension exerted on the arm it by the cable 38 drops to eight pounds and consequently spring 33 takes control and moves the arm into the position shown in Figure 1 opening microswitch 31 and stopping the stranding machine.

It will be obvious that the stationary pulley may be omitted and the cable led directly from the twisting die around a single pulley mounted on the pivoted arm and thence to the drawing capstan. It will likewise be obvious that by increasing the number of pulleys and consequently increasing the number of wire wraps the tension may be multiplied as many times as is desired. Also, by adjusting the spring 33 the difierential upon which the switch will be actuated may be modified. Consequently, while we have described the preferred embodiment of our invention it will be understood that modifications may be made within the scope thereof. We wish therefore to be limited not by the foregoing description which was given solely for purposes of illustration but only by the claims granted us.

What is claimed is:

1. In a safety switch structure for wire stranding machines and adapted to be operationally located between the twisting die and the drawing capstan of the stranding machine, in combination, a pivoted arm, a pulley on said pivoted arm, said pulley being adapted to have a stranded cable wrapped around it in advance of the drawing capstan, an adjustable spring bearing against said pivoted arm and a switch mounted adjacent said pivoted arm adapted to be operated by movement of said swinging arm resulting from a decrease in tension on the cable.

2. A device as claimed in claim 1, characterized in that a shouldered screw is mounted adjacent said pivoted arm, said screw being provided with a pair of washers said adjustable spring extends between said pair of washers, one of said washers seating on the shoulder of said screw and the other against said pivoted arm, said screw being threadedly mounted in a support to thereby adjust the pressure exerted by said spring.

3. A device as claimed in claim 1, characterized in that said pivoted arm is provided with a screw threadedly mounted therein, said screw serving to make contact with said switch to open the switch.

4. A device as claimed in claim 1, characterized in that a shouldered screw is mounted adjacent said pivoted arm, said screw being provided with a pair of washers said adjustable spring extends between said pair of washers, one of said washers seating on the shoulder of said screw, said screw being threadedly mounted to thereby adjust the pressure exerted by ,said spring, said pivoted arm being provided with a screw threadedly mounted therein, said screw serving to make contact with said switch to open the switch.

5. In a safety switch for wire stranding machines and the like, in combination, at least one pulley on a fixed axis, a plurality of pulleys cooperating with said one pulley, a pivoted arm on which said second mentioned pulleys are mounted for movement toward and away from said first 4 i mentioned pulley, said pulleys being adapted to have a stranded cable wrapped about them in advance of the drawing capstan, an adjustable spring bearing against said pivoted arm and a switch mounted adjacent said swinging arm and adapted to be operated by movement of said swinging arm resulting from a decrease of tension on the cable.

6. A device as claimed in claim 5, characterized in that a shouldered screw is mounted adjacent said pivoted arm, said screw being provided with a pair of washers said adjustable spring extends between said pair of washers, one of said w hers seating on the shoulder of said screw and; the other against said pivoted arm, said screw being threadedly mounted to thereby adjust the pressure exerted by said spring.

7. A device as claimed in claim 5, characterized in that said pivoted arm is provided with a screw threadedly mounted therein, said screw serving to make contact with said switch to open the switch.

8. A device as claimed in claim 5, characterized in that a shouldered screw is mounted adjacent said pivoted arm, said screw being provided with a pair of washers said adjustable spring extends between said pair of washers, one of said washers seating on the shoulder of said screw and the other against said pivoted arm, said screw being threadedl mounted to thereby adjust the pressure exerted by said spring, said pivoted arm being provided with a screw threadedly mounted therein, said screw serving to make contact with said switch to open the switch.

9. In a safety switch for wire stranding machines and the like, in combination, a plurality of pulleys rotatably mounted on a. support, a second plurality of pulleys mounted in line with said first mentioned pulleys, said second mentioned pulleys beng mounted on the end of a pivoted arm, said first and second mentioned pulleys being adapted to receive a number of wraps of cable from the stranding machine, which cable is under tension exerted by a drawing capstan, means for exerting adjustable spring pressure against said pivoted arm in a direction opposite to the tension exerted by the wraps of cable about said pulleys, and a switch operated by said pivoted arm upon a decrease in tension in the cable.

CARL O. BRUESTLE.

HUGO WILKEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,113,698 Larmuth Apr. 12, 1938 FOREIGN PATENTS Number Country Date 691,675 Germany June 3, 1940 

